An evaluation of various direct

compression excipients using the

Gamlen Tablet Press GTP-1

Dipankar Dey PhD

Technical Manager

Gamlen Tableting Ltd

Motivation: Tablet Formulation

• The modern tablet

needs to satisfy

numerous properties

that make it ‘Fit for

Purpose’

• Physicochemical

• Stability

• Manufacturing

Drug Substance

Excipients

Lubricant

Tablet

2

Tablet Formulation Experimentation

• API availability

• Equipment

Our approach

• Milligram quantities of material

• Objective method

• Practical

The Gamlen Tablet Press GTP-1• Ideal instrument

for formulation

development

• Bench top

computer

controlled

• Milligram

quantities of

material

• Dual mode-

tablet press and

strength tester

Computer control

• Can be linked to any laptop or PC.

• Real time data recording.

• Force displacement curves.

• Ejection force.

• Fracture load of compact.

Tablet tensile strength

• Most important

tablet physical

parameter

• Objective as it

takes into account

not only tablet

hardness but

tablet thickness

too

• Scaleable to

different size and

shapes of tablets

Making valid comparisons

Evaluating compressibility• Tensile

strength measured over a range of forces

• Enables ranking of formulations

• Example of DC v wet granulated blend

Compressibility assessment

Development of a DC paracetamol

tablet

Main experiments

Selection of 3 most compressible formulations

Preliminary experiments

10% paracetamol0.5% MgSt

8 x mannitol

2-x isomaltulose

Methods

• 100g blends were made using a Turbula mixer

• 75mg round, flat faced 5mm tablets made at 5 different compression forces

• Tablets subjected to fracture, friability and disintegration testing

• Powder flow properties also tested

Ejection stress calculation

dt

�� ��

���

ES= ejection stress (MPa)

F= ejection force (N)

d = diameter of tablet (mm)

t = thickness of tablet (mm)

Preliminary experiments: Friability

Screening

Parteck M200

Perlitol 200SD

Galen IQ721

L-HPC21

Main expts: Friability

Summary• Compressibility is a

useful approach to screen formulations

• GTP generates useful comparative data to help evaluate different grades of excipient and drug content

• A ‘Decision matrix’ is a useful way of visualizing the data

Contact details

Dr Dipankar Dey

Gamlen Tableting Ltd.

Biocity Nottingham

Nottingham NG1 1GF UK

Tel: +44 7712 632735

Fax: +44 115 912 4278

Email: dip@gamlen.co.uk

http://www.gamlen.co.uk